As a configuration example of a known heat-dissipating structure of the related art, FIG. 9 shows a heat-dissipating structure 3 including a heat sink 70, a heat block 20, and a thermally conductive sheet 60 interposed between the heat sink 70 and the heat block 20. The heat block 20 of the heat-dissipating structure 3 is in contact with a heat generator 50 provided on, for example, a printed circuit board 40. Thus, heat generated by the heat generator 50 is dissipated to the outside along a heat dissipation route HR2 where the heat from the heat generator 50 sequentially passes through the heat block 20, the thermally conductive sheet 60, and the heat sink 70.
In this configuration, the thermally conductive sheet 60 accommodates dimensional tolerances in the thickness direction of the components and erection tolerances between the components. In this case, the tolerances mean variations caused by small undulations or slopes on the surfaces of the components and machining/assembly. The accommodation of these tolerances secures adhesion between the heat sink 70 and the heat block 20.
As shown in FIG. 10, Japanese Patent Laid-Open No. 2005-327940 (Patent Literature 1) discloses a heat-dissipating structure 4 including a heat sink 80 having a projecting portion and a thermally conductive sheet 60 in contact with the projecting portion of the heat sink 10. In this configuration, a through hole is formed on a printed circuit board 40 and the projecting portion of the heat sink 80 is fit into the through hole of the printed circuit board 40, locating the thermally conductive sheet 60 between the heat generator 50 and the projecting portion of the heat sink 80. Thus, heat generated by the heat generator 50 is dissipated to the outside along a heat dissipation route HR3 where the heat from the heat generator 50 sequentially passes through the thermally conductive sheet 60 and the heat sink 80.